The Immune System Overview

These flashcards cover key terms and definitions related to the immune system and infectious diseases.

Infectious Disease

A disease caused by a living organism (pathogen) within your body.

Pathogens

Organisms that cause disease.

Bacteria

Single-celled organisms that can infect and damage cells directly or produce toxins.

Virus

Tiny non-living particles that must invade a host cell to replicate and can damage or kill the host cell.

Fungi

Organisms such as molds and yeasts that can cause diseases like athlete's foot.

Protists

Microscopic organisms that do not fit well into any other classification and can cause diseases like malaria.

The Immune System

The body's defense against disease-causing organisms, malfunctioning cells, and foreign particles.

First Line of Defense

Physical and chemical barriers such as skin, breathing passages, saliva, and stomach acid that keep pathogens out.

Inflammatory Response

A reaction to tissue damage that includes symptoms like redness, swelling, heat, and pain.

T-Cells

White blood cells that can recognize and kill infected human cells and cancer cells.

B-Cells

White blood cells that produce antibodies specific to each pathogen.

Antibodies

Proteins produced by B-cells that mark pathogens for destruction.

Active Immunity

Immunity developed by exposure to a pathogen or vaccination, resulting in a protective immune response.

Passive Immunity

Immunity acquired by receiving antibodies from another source, such as a mother passing immunities to her baby.

AIDS

Acquired Immune Deficiency Syndrome, caused by the Human Immunodeficiency Virus (HIV), which targets and kills T-cells.

Vaccine

A preparation that introduces antigens into the immune system to produce immunity.